An antenna system of this generic type is known from DE 10 2012 208 303 [US 2015/0123854]. The antenna system disclosed therein (referred to as an antenna module) has a housing holding a printed-circuit board. This printed-circuit board is referred to as an antenna circuit board. Several antenna elements of the same type or of different types are provided on the upper face of the antenna circuit board, each of which has its respective connections on the antenna circuit board. Shield plates are provided between the antenna elements so that the high-frequency signals emitted from and/or received by them do not interfere with each other.
The lower face of the circuit board carries electronic circuits that further process the high-frequency signals received from the antenna elements or process signals to be emitted by the antenna elements. Additional shield plates are, in turn, provided beneath the antenna circuit board in order to block high-frequency emissions from the antenna module or incident radiation into the antenna module. The electronic circuits are in contact with the connections of the antenna elements, so that the connections (also called the base point) of the antenna element is connected directly to the respective electronic circuit. The antenna elements are provided under an outer cover. The antenna module is guided with its outer cover through an aperture in a body panel of a vehicle, so that, on the one hand, the antenna elements beneath the outer cover project past the surface of the body panel and the high-frequency signals to be received can be reached by the antenna elements. Moreover, this makes it possible for the antenna elements to emit high-frequency signals without being blocked so by the body panel made of an electrically conductive material. On the other hand, the housing of the antenna module is provided beneath the body panel so that it can be provided and fastened in this installation space.
The electronic circuits provided on the antenna circuit board therefore also operate in the high-frequency range, for which reason it is necessary to provide shield plates beneath the antenna circuit board. Moreover, the electronic circuits therefore operate not only in the high-frequency range, but also in the intermediate and low-frequency range as well.